Unwanted photo-induced changes of the refractive index greatly limit the application of lithium niobate crystals for nonlinear-optical devices. Conventional approaches to prevent this so-called "optical damage" focus either on reduction of photorefractive centers or on ways to increase the electron conductivity. An alternative might be to increase the ionic part of the dark conductivity. We present a first study of this approach, comparing at various temperatures optical damage in lithium niobate crystals with different H<sup>+</sup> concentrations.
© 2003 Optical Society of AmericaPDF Article